Noiseless typewriter



March 16, 1937 OUVETT. A 2,073,902

NOISELES S TYPEWR I'I'ER Filed Oct. 3, 1935 2 Shets-Shet 2 lNVENTORCAMILLO OLIVETTI 7 B I 0&2 I

' AT ORNEV Patented Mar. 1.6, 1937 HPATENT OFFICE" 'ap'lasoz NOISELESSCamille Olivetti, lv'rea, Italy Application ottom- :i, 1935, erial No.43,438

In Italy October 2'1, 1934 9 Claims. (01. rev-22) It is well known thatone of the greatest difflculties usually met in the construction ofnoiseless typwriters lies in the necessity of giving a ate the typelevers, in order not to lose in the elastic deformation of these parts aconsiderable amount of the *power available for the writin operation,thus lowering the efficiency of the typewriter. I

My invention involves a new principle, whereby, at the moment ofprinting,'the paper carrying platen is advanced and pressed against thetype, The platen is advanced to the position in which a print is made bymeans of a kinematic mechald nism so designed that, when the key on thekeyboard is pressed, thespeed of the type lever will be graduallyreduced to zero and the type will be held firmly against the movingplaten until the print is accomplished.

2.0 The operation andthe advantages of a typewriter embodying myinvention will be better.-

understood by considering the following:

If the paper carrying platen were extremely light, it would be necessaryto impart to it a very of sufficient magnitude to equalize the printingwork. This manner of operating would be substantially the same as takesplace inthe prior art typewriters, though obtained by a wholly differentmechanism. If, on the contrary, the,

a proper choice of the weight of the paper carrying platen a suflicientkinetic energy can be imparted to it even with a low speed or a shortmotion, and that the approaching speed of the platen can be held withinso small a limit that, the noise resulting from the stroke will beextremely reduced.

A further advantage of the present invention will be found consideringthat, as will be better explained, itis possible to regulate withinample limits the time during which the paper is pressed against thetype; moreover, this fraction of time will be longer than in the priorart models, withv out in the least lowering the typing speed. Also, theprint is substantially improved, as it is well known that the longer thepressure the greater 55 the quantity of ink transferred from the ribbonmarked rigidity to the movable parts which actuthe type firmly whenthepaper high speed in order to obtain a kinetic energy' (placed asusual between the type and the paper) to the paper.

While the following specifications and the-accompanying drawings show anembodiment of the present invention, it is apparent that any otherdevice which will perform on the above-mentioned principle may beregarded as suitable.

As'will be better explained later, the paper carrying platen is actuatedby means of a. spring which is loaded, every time a print is made, bythe so called universal bar. Therefore, it is the pressure of thetypists finger on the key which causes the forward motion of the papercarrying platen; however, this motion can be obtained in many otherways. I

The type bar mechanism may be varied too; as a matter of'fact, any kindof connection will be suitable if capable of slowing down the motion ofthe type when the latter approaches the position 'in which a print is tobe made and holding carrying platen is pressed against-it. I

In the accompanying drawings; Figure 1 is a. fragmentary sectional viewshowing the type bar mechanism in the position 1 of rest;

Fig.2 is a similar view showing the type bar mechanism in the printingposition;

Fig. 3 is a'similar view showing the type ha mechanism in the positionin which a print is not yet made but the type bar is held standing whilethe platen is beginning its forward motion; and r Fig. 4 and 5 aredetail views of the linkage used to determine the forward motion of theplaten.

With reference to Fig. 1, the key lever l is pivoted at 2 and, throughlever 3 pivoted at I, rocks lever 5 about its fulcrum B.- The end oflever 5 carries a stud I slidably positioned in a slot 8 cut in thelever 9 pivoted at Ill. The slot 8 is so designed in correspondence withthe operating lever 5 that the speed of lever 9, very slow at thebeginning of its stroke, is evenly accelerated as the stud 'l approachesthe hearing or pivot ll) of the type lever 9, again reduced as the. studmoves away from pivot l0 and flnally stopped in the printing positionwhen the longi-J 'tudinal axis of the slot is tangent to the circledescribed by the stud I. It will be noted that in this position afurther pressure on the key will only hold the type still, withouteffecting a backward movement of the type. Consequently, this structurewill easily withstand the thrust from the paper carrying platen.

The platen is fixed to the frame |2 of the carriage by means of aparallel linkage composed of two cranks l3 and H and a T-shapedconnecting rod l5 which will restrict motion of the 5 platen 'to ahorizontal direction, perpendicular to the axis of the platen. A slot 31is formed in the upper vartical portion of connecting rod l5 whichprovides a bearing for the shaft of the paper carrying platen so thatthe latter can assume a vertical motion, whereby each one of the typescarried by the type lever can strike on the platen.

A bar linkage of this type is provided at both ends of the papercarrying platen and the two connecting rods or bars l5 are coupledtogether by a rod l6 of the same length as the platen. This rod I6 isengaged by a forked lever pivoted at l6 which serves to impart to thepaper carrying platen a small transverse motion toward and away from thetype without interfering with the lateral shift of the whole carriage. Aspring l9 urges lever against a stop 20 and the platen toward theposition in which a print will be made. The type levers 9 are cam-shapedin the proximity of their bearing, so that they can operate theuniversal bar 2|. As is well known, the

universal bar actuates the escapement and the For this operation, anysuitable mechanism can be used. In the mechanism shown in -the drawings,lever I1 is controlled by a toggle linkage composed r two links 22 andas. Link 22 is piv- 40 otally connected to the end of lever l1 and link23 is pivoted on the frame at 24. Link 23 is forkshaped at one end (seeFigs. 1 and 5) and supports (in the proximity of, and perpendicularlyto, shaft 26) a swinging lever 26 provided with 45 two lugs 21 and 28.Lever 26 is pivotally mounted on stud 25 so that lugs 21 and 28 mayalternatively be shifted to register with two other lugs 29 and 36provided on the moving plate 3|. Cranks 32 and 33 are pivotally mountedat their 50 lower ends to the frame of the machine and carry at-theirupper ends the plate 3|. Motion is imparted from the universal bar 2| toplate 3| by means of a rod 34 and a lever 35 pivoted at 36.

55 Fig. 4 represents a front view of the swinging lever 26 and shows asection of the lugs 29 and 36 of plate 3|.

In the position of rest, as shown in Fig. 1, the links 22 and 23 are outof alignment and lug 21 60 on the swinging lever is opposite lug 29 ofplate 3|. When plate 3 actuated by the universal bar, advances, lug 29engages lug 21 and compels link 23 and the swinging lever 26 to revolvearound stud 24. The two links 22 and 23 are now in 65 the same line, asshown in Fig. 3, and they compel lever H to rotate ina clockwisedirection around bearing l8, loading the spring I9 and shifting thepaper carrying platen to a position away from the type.

70 Upon further motion of the universal bar and the consequent advanceof plate 3|, the toggle links 22 and 23 pass over their dead centerposition and lever I1 is permitted to rotate counterclockwise under theaction of spring l9, bringing 75 the whole system in the position shownin Fig. 2

and pushing the paper carrying platen against the type, as the typelever 9 has in the meantime reached its final position. An impression ismade and spring 39, pulling on lever 5, causes it to rotate clockwise toreturn the type lever mecha- 5 nism to its rest position, while spring36 returns the universal bar and all the parts connected to it to theirrest position.

On account of the sudden swinging of links 22 and 23, the lug 21 ofswinging-lever 26 is disl0 engaged from lug 29 of plate 3| and lug 28 isshifted to a position alongside of'lug 36 which it retains until plate3| is returned to the rest position together with the universal bar.

'At the next stroke, in order to obtain the same 16 movement of thevarious parts it is necessary that lug engage against lug 28 of swinginglever 26. Therefore, lever 26 must be shifted to move lug 28 into thepath of travel of lug 36, while lug 21 must be moved to a position outof 20 the path of travel of lug 29. This is effected by a small leafspring 4| horizontally fixed on the typewriter frame at 42. Its free endis engaged between two studs and 36 provided on arm flofthe swinginglever 26; the latter, as already 25 stated, is pivoted at 25 on thefork-shaped extremity of rod 23. The leaf spring is also engaged betweentwo studs 43 and 44 provided on link 22. When the links 22 and 23, whichcompose the toggle linkage, are shifted upwards or 30 downwards, theleaf spring is bent in the same direction and actuates, through studs 46and 46, the swinging lever in such a way that lug 2'! will be in thepath of lug 29 when the linkage is shifted upwards, while lug 28 will bein the path 35 of lug 36 when the linkage is shifted downwards.

When the toggle linkage, during the operation of the typewriter,suddenly alters its position, the elasticity of the spring 4| allows thelugs 21 or 28 of swinging lever 26 to slide laterally on plate 3|, thustaking the right position with regard to the path of travel of plate 3|when the return stroke is nearly completed.

As already stated, the above-described mechanism isonly one of the manymechanisms for carrying out the present invention.

The forward motion of the paper carrying platen is, in the describedexample, obtained through the links 22 and 23 by means of the thrust ofspring l9 in such a way that the acceler- 50 ation of said platen ispositive. With other sys: tems, this acceleration may be negative oreven zero, i. e., the paper carrying platen will advance with a constantspeed.

The different ways of eflecting this mechanism are to be determined withreference to the weight of the platen, in correspondence with thevarious characteristics which it is desired that the typewriter possess.This may preferably be eminently dynamic (corresponding to a quick mo-00 tion of the paper carrying platen) or eminently static (low motion ofthe platen, but high thrust between paper and type) in consequence ofwhich the typewriter will be more or less noiseless with reference toother characteristics.

Anyway, it shall be understood. that my invention is based on thesimultaneous movement of a type bar mechanism which will bringthe typeinto the printing position with a reduced motion and hold it firmly fora fraction of time while another mechanism, controlled by the universalbar which is pressed by the typist, serves to push forward the papercarrying platen to press it against the type.

Incidentally, it should be noted that the initial I position of the P pr rryi platen may be .16

possessing a residual speed, or just when the type is standing still, oreven when it has already begun its backward motion. In the latter case,

the action of printing is effected through the differential speed of thetype bar and .the paper carrying platen.

I claim:

1 In a typewriter of the character described. a plurality of type, meansfor advancing the type to a printing position, a platen shiftable towardand away from the printing position of the type, and means operable uponadvancing the type from a position of rest to the printing position toshift the platen away from the printing position and then advance thesame to the printing position to engage the type.

2. In a typewriter of the character described, a plurality of type,means for advancing the type to a printing position, a platen shiftabletoward and away from the printing position of the type, and meansincluding a toggle linkage operable upon advancing the type from aposition of rest to the printing position to shift the platen away fromthe printing position and then advance the same to the printing positionto engage the type.

3. In a typewriter of the character described, a plurality of type,means for advancing the type to a printing position, a platen shiftabletoward and away from the printing position of the type,

. resilient means urging said platen to the printing position, and meansoperable upon advancing the type to the printing position for shiftingthe platen away from the printing position and allowing it to returnunder the action of the resilient means. t

4. In a typewriter of the characterdescribed, a plurality of type, meansfor advancing the type to a printing position, a platen shiftabie towardand away from the printing position of the type, resilient means urgingsaid platen to the printing position, and means including a togglelinkage operable upon advancing the type to the printing position forshifting the platen away from the printing position and allowing it toreturn under the action of the resilient means.

5. In a typewriter of the character described, a plurality of type bars,means for advancing the type bars to a printing position, a "platenshiftable towards and away from the type of the type bars when thelatter are in printing position, re silient means urging said platentoward the printing position, a universal bar actuated by the type bars,and means actuated by said universal bar for shifting the platen awayfrom theprinting position during advance of the type bars, to theprinting position and allowing the same to return under the action ofthe resilient means when the type bars arrive at the printing position.

6. In a typewriter of the character described, a plurality of type bars,means ior'advancing the type bars to a printing position, a platenshiftable towards and away from the type of the type bars when thelatter are in printing position, resilient means urging said platentoward the printing position, a universal bar actuated by the type bars,

and means including a toggle linkage actuated by said universal bar forshifting the platen away from the printing position during advance ofthe type bars to the printing position and allowing the same to returnunder the action of the rosili- I ent means when the type bars arrive atthe printing position.

7. In a typewriter of the character described, a plurality of type bars,means for advancing the type bars to a printing position, a platenshiftable towards and away from the type of the type bars when thelatter are in printing position, resilient means urging said platentoward the printing position, a universal bar actuated by the type bars,a toggle linkage comprising a pair of connected links, the first ofwhich has its free end connected to the platen and the second of whichhas its free end mounted on a stationary pivot, and means actuated bysaid universal bar during advance of the type bars to a printingposition for shifting said linkage from a position wherein the links areat an angle to each other through a' position wherein the links arealigned, to move the platen away from the printing position, to aposition wherein the links are again at an angle to each other. to allowthe resilient means to return the platen tolthe printing position. v

8. In a typewriter of the character described, a plurality of type bars,means for advancing the type bars to a printing position, a platenshiftable towards and away from the type of the type bars'when thelatter are in printing position, resilient means urging said platentoward the printing position, a universal bar actuated by the type bars,a toggle linkage comprising a pair of connected links, the first ofwhich has its 'free end connected to the platen and the second of whichhas its free end mounted on a stationary pivot, a rocker arm carriedby'said second link and shlftable in a plane perpendicular to the centerline of the second link, lugs carried by the ends of said rocker arm,and means actuated by said universal bar for engaging one of said lugsto shift the linkage through its dead center to move the platen awayfrom the printing position and when the latter are in printing position,resilient means urging said platen toward the printing position, auniversal bar actuated by the type bars, a toggle linkage comprising apair of connected links, the first of which has its free end connectedto the platen and the second of which has its free end mounted on astationary pivot, a rocker arm carried by said second link and shiftablein a plane perpendicular to the center line of the second link, lugscarried by the ends of said rocker arm, a member provided with a pair oflugs to engage the lugs on said rocker arm, means'actuated by saiduniversal bar for moving said member toward said rocker arm to shift thetoggle linkage through its dead center and move the platen away from theprinting position and allow it to return under the action of theresilient means, and means associated with said toggle linkage andoperable upon passage of said linkage through its dead center forshifting said rocker arm to place the lug at one end in the path 01travel of a lug on the member and to place the lug on the other end outof the path of travel of a lug on said member.

CAMILLO OLIVETTI.

